pred = torch.zeros(y_test.shape) index = 0 test_loader = torch.utils.data.DataLoader(torch.utils.data.TensorDataset(x_test, y_test), batch_size=1, shuffle=False) with torch.no_grad(): for x, y in test_loader: test_l2 = 0 x, y = x.cuda(), y.cuda() out = model(x) pred[index] = out test_l2 += myloss(out.view(1, -1), y.view(1, -1)).item() print(index, test_l2) index = index + 1
时间: 2023-12-06 11:03:25 浏览: 118
这段代码看起来像是用 PyTorch 实现的一个测试过程,其中包含以下步骤:
1. 首先定义了一个全零的 tensor `pred`,与 `y_test` 的形状相同,用于存储模型的预测结果。
2. 然后创建了一个 DataLoader,用于将测试数据按照指定的 batch_size 进行分批处理。这里的 batch_size 设为 1,表示每次只处理一个样本。
3. 接着使用 `torch.no_grad()` 语句块,表示在测试过程中不需要进行梯度计算,以减少内存占用和计算时间。
4. 在 for 循环中,每次读取一个 batch 的数据,将其转移到 GPU 上(如果有的话),然后用模型进行前向计算得到预测结果,并将其存储到 `pred` 中。
5. 计算当前 batch 的 loss 值,并将其加到 `test_l2` 变量中。
6. 最后打印出当前 batch 的 index 和 loss 值,同时将 index 加 1,进入下一个 batch 的处理过程。
总的来说,这段代码的作用是用训练好的模型对测试数据进行预测,并计算出测试集上的 loss 值。
相关问题
LDAM损失函数pytorch代码如下:class LDAMLoss(nn.Module): def init(self, cls_num_list, max_m=0.5, weight=None, s=30): super(LDAMLoss, self).init() m_list = 1.0 / np.sqrt(np.sqrt(cls_num_list)) m_list = m_list * (max_m / np.max(m_list)) m_list = torch.cuda.FloatTensor(m_list) self.m_list = m_list assert s > 0 self.s = s if weight is not None: weight = torch.FloatTensor(weight).cuda() self.weight = weight self.cls_num_list = cls_num_list def forward(self, x, target): index = torch.zeros_like(x, dtype=torch.uint8) index_float = index.type(torch.cuda.FloatTensor) batch_m = torch.matmul(self.m_list[None, :], index_float.transpose(1,0)) # 0,1 batch_m = batch_m.view((16, 1)) # size=(batch_size, 1) (-1,1) x_m = x - batch_m output = torch.where(index, x_m, x) if self.weight is not None: output = output * self.weight[None, :] target = torch.flatten(target) # 将 target 转换成 1D Tensor logit = output * self.s return F.cross_entropy(logit, target, weight=self.weight) 模型部分参数如下:# 设置全局参数 model_lr = 1e-5 BATCH_SIZE = 16 EPOCHS = 50 DEVICE = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu') use_amp = True use_dp = True classes = 7 resume = None CLIP_GRAD = 5.0 Best_ACC = 0 #记录最高得分 use_ema=True model_ema_decay=0.9998 start_epoch=1 seed=1 seed_everything(seed) # 数据增强 mixup mixup_fn = Mixup( mixup_alpha=0.8, cutmix_alpha=1.0, cutmix_minmax=None, prob=0.1, switch_prob=0.5, mode='batch', label_smoothing=0.1, num_classes=classes) 帮我用pytorch实现模型在模型训练中使用LDAM损失函数
好的,以下是使用 LDAM 损失函数训练模型的代码示例:
```python
import torch
import torch.nn as nn
import torch.optim as optim
import torch.nn.functional as F
from torchvision import datasets, transforms
from ldam_loss import LDAMLoss # 假设你已经将 LDAM 损失函数的代码存放在 ldam_loss.py 文件中
# 设置全局参数
model_lr = 1e-5
BATCH_SIZE = 16
EPOCHS = 50
DEVICE = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')
use_amp = True
use_dp = True
classes = 7
resume = None
CLIP_GRAD = 5.0
Best_ACC = 0
use_ema = True
model_ema_decay = 0.9998
start_epoch = 1
seed = 1
# 设置随机种子
def seed_everything(seed):
torch.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
np.random.seed(seed)
random.seed(seed)
seed_everything(seed)
# 数据增强 mixup
mixup_fn = Mixup(
mixup_alpha=0.8,
cutmix_alpha=1.0,
cutmix_minmax=None,
prob=0.1,
switch_prob=0.5,
mode='batch',
label_smoothing=0.1,
num_classes=classes
)
# 加载数据集
train_loader = torch.utils.data.DataLoader(
datasets.CIFAR10('./data', train=True, download=True, transform=transforms.Compose([
transforms.RandomCrop(32, padding=4),
transforms.RandomHorizontalFlip(),
transforms.ToTensor(),
transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))
])),
batch_size=BATCH_SIZE, shuffle=True, num_workers=4, pin_memory=True
)
test_loader = torch.utils.data.DataLoader(
datasets.CIFAR10('./data', train=False, transform=transforms.Compose([
transforms.ToTensor(),
transforms.Normalize((0.5, 0.5, 0.5), (0.5, 0.5, 0.5))
])),
batch_size=BATCH_SIZE, shuffle=False, num_workers=4, pin_memory=True
)
# 定义模型
class Net(nn.Module):
def __init__(self):
super(Net, self).__init__()
self.conv1 = nn.Conv2d(3, 6, 5)
self.pool = nn.MaxPool2d(2, 2)
self.conv2 = nn.Conv2d(6, 16, 5)
self.fc1 = nn.Linear(16 * 5 * 5, 120)
self.fc2 = nn.Linear(120, 84)
self.fc3 = nn.Linear(84, 10)
def forward(self, x):
x = self.pool(F.relu(self.conv1(x)))
x = self.pool(F.relu(self.conv2(x)))
x = x.view(-1, 16 * 5 * 5)
x = F.relu(self.fc1(x))
x = F.relu(self.fc2(x))
x = self.fc3(x)
return x
# 初始化模型和优化器
model = Net().to(DEVICE)
optimizer = optim.Adam(model.parameters(), lr=model_lr)
# 如果 resume 不为空,则从指定的 checkpoint 恢复模型和优化器
if resume is not None:
checkpoint = torch.load(resume)
model.load_state_dict(checkpoint['model'])
optimizer.load_state_dict(checkpoint['optimizer'])
start_epoch = checkpoint['epoch'] + 1
Best_ACC = checkpoint['Best_ACC']
print(f"Resuming from checkpoint {resume}, epoch {start_epoch}")
# 使用 LDAM 损失函数
cls_num_list = [1000] * classes
criterion = LDAMLoss(cls_num_list, max_m=0.5, s=30).to(DEVICE)
# 训练模型
for epoch in range(start_epoch, EPOCHS + 1):
train_loss = 0
train_acc = 0
model.train()
for batch_idx, (data, target) in enumerate(train_loader):
data, target = data.to(DEVICE), target.to(DEVICE)
data, target_a, target_b, lam = mixup_fn(data, target) # mixup 增强
optimizer.zero_grad()
output = model(data)
loss = lam * criterion(output, target_a) + (1 - lam) * criterion(output, target_b) # 计算 mixup 后的损失函数
loss.backward()
if CLIP_GRAD:
torch.nn.utils.clip_grad_norm_(model.parameters(), CLIP_GRAD) # 梯度裁剪
optimizer.step()
train_loss += loss.item() * data.size(0)
pred = output.argmax(dim=1, keepdim=True)
train_acc += pred.eq(target.view_as(pred)).sum().item()
train_loss /= len(train_loader.dataset)
train_acc /= len(train_loader.dataset)
# 计算测试集上的损失和准确率
test_loss = 0
test_acc = 0
model.eval()
with torch.no_grad():
for data, target in test_loader:
data, target = data.to(DEVICE), target.to(DEVICE)
output = model(data)
test_loss += F.cross_entropy(output, target, reduction='sum').item()
pred = output.argmax(dim=1, keepdim=True)
test_acc += pred.eq(target.view_as(pred)).sum().item()
test_loss /= len(test_loader.dataset)
test_acc /= len(test_loader.dataset)
# 更新 Best_ACC 并保存模型
if test_acc > Best_ACC:
Best_ACC = test_acc
state = {
'model': model.state_dict(),
'optimizer': optimizer.state_dict(),
'epoch': epoch,
'Best_ACC': Best_ACC
}
torch.save(state, f'model_epoch_{epoch}_acc_{Best_ACC:.4f}.pth')
# 打印训练日志
print(f"Epoch {epoch}/{EPOCHS}: train_loss={train_loss:.4f} train_acc={train_acc:.4f} test_loss={test_loss:.4f} test_acc={test_acc:.4f}")
```
这里使用的是 CIFAR-10 数据集和一个简单的卷积神经网络模型,你需要将其替换成你自己的数据集和模型。
编写pytorch代码,定义LSTMAttention模型,定义一个CPSO优化算法,用FA_CPSO算法有优化模型中神经元个数、dropout比率、batch_size、学习率等超参数,将优化好的超参数传递给模型,在特征训练集X_train.csv和标签训练集y_train.csv上训练模型,将最优的参数设置给模型,在特征测试集X_test.csv和标签测试集y_test.csv上测试模型,进一步优化模型,将优化后的参数设置给模型,并输出测试损失,绘制测试集的预测值和实际值,计算测试集的均方根误差,在预测集上进行预测,设定标签数据最大值的85%为警戒线,绘制预测集的实际值到达的时间和预测值到达的时间
好的,我可以帮你解答这个问题。首先是定义LSTMAttention模型的pytorch代码:
```python
import torch
import torch.nn as nn
class LSTMAttention(nn.Module):
def __init__(self, input_size, hidden_size, output_size):
super(LSTMAttention, self).__init__()
self.hidden_size = hidden_size
self.lstm = nn.LSTM(input_size, hidden_size, batch_first=True)
self.attention_layer = nn.Linear(hidden_size, 1)
self.fc = nn.Linear(hidden_size, output_size)
self.softmax = nn.Softmax(dim=1)
def forward(self, inputs):
lstm_out, _ = self.lstm(inputs)
attention_scores = self.attention_layer(lstm_out)
attention_weights = self.softmax(attention_scores)
context_vector = torch.sum(attention_weights * lstm_out, dim=1)
output = self.fc(context_vector)
return output
```
上面代码中,`LSTMAttention`类继承自`nn.Module`,定义了一个带有注意力机制的LSTM模型。其中,`input_size`表示输入特征的维度,`hidden_size`表示LSTM隐藏层的维度,`output_size`表示输出的维度。
然后是定义CPSO优化算法的代码:
```python
import numpy as np
class CPSO:
def __init__(self, num_particles, num_dimensions, max_iterations, objective_func):
self.num_particles = num_particles
self.num_dimensions = num_dimensions
self.max_iterations = max_iterations
self.objective_func = objective_func
self.particles = np.random.uniform(0, 1, size=(num_particles, num_dimensions))
self.velocities = np.zeros((num_particles, num_dimensions))
self.best_positions = self.particles.copy()
self.best_scores = np.zeros(num_particles)
for i in range(num_particles):
self.best_scores[i] = self.objective_func(self.best_positions[i])
self.global_best_position = self.best_positions[self.best_scores.argmin()]
self.global_best_score = self.best_scores.min()
def optimize(self):
for iteration in range(self.max_iterations):
for i in range(self.num_particles):
r1 = np.random.uniform(0, 1, size=self.num_dimensions)
r2 = np.random.uniform(0, 1, size=self.num_dimensions)
self.velocities[i] = self.velocities[i] + r1 * (self.best_positions[i] - self.particles[i]) + r2 * (self.global_best_position - self.particles[i])
self.particles[i] = self.particles[i] + self.velocities[i]
self.particles[i] = np.clip(self.particles[i], 0, 1)
score = self.objective_func(self.particles[i])
if score < self.best_scores[i]:
self.best_scores[i] = score
self.best_positions[i] = self.particles[i]
if score < self.global_best_score:
self.global_best_score = score
self.global_best_position = self.particles[i]
return self.global_best_position
```
上面代码中,`CPSO`类接受四个参数:`num_particles`表示粒子数,`num_dimensions`表示维度数,`max_iterations`表示最大迭代次数,`objective_func`表示目标函数。在初始化时,我们随机初始化粒子的位置和速度,并计算出每个粒子的最优位置和最优得分,以及全局最优位置和最优得分。在优化过程中,我们根据公式更新粒子的速度和位置,并更新每个粒子的最优位置和最优得分,以及全局最优位置和最优得分。最终返回全局最优位置。
接下来是使用FA_CPSO算法优化模型中的超参数的代码:
```python
import pandas as pd
from sklearn.model_selection import train_test_split
from sklearn.metrics import mean_squared_error
from functools import partial
# 加载数据
X_train = pd.read_csv('X_train.csv')
y_train = pd.read_csv('y_train.csv')
X_test = pd.read_csv('X_test.csv')
y_test = pd.read_csv('y_test.csv')
# 定义目标函数
def objective_func(params, X_train, y_train):
# 解析参数
num_neurons, dropout_rate, batch_size, learning_rate = params
# 定义模型
model = LSTMAttention(input_size=X_train.shape[2], hidden_size=num_neurons, output_size=1)
loss_fn = nn.MSELoss()
optimizer = torch.optim.Adam(model.parameters(), lr=learning_rate)
# 训练模型
train_dataset = torch.utils.data.TensorDataset(torch.tensor(X_train.values).float(), torch.tensor(y_train.values).float())
train_loader = torch.utils.data.DataLoader(train_dataset, batch_size=batch_size, shuffle=True)
for epoch in range(10):
for X_batch, y_batch in train_loader:
optimizer.zero_grad()
y_pred = model(X_batch)
loss = loss_fn(y_pred, y_batch)
loss.backward()
optimizer.step()
# 计算测试误差
y_pred = model(torch.tensor(X_test.values).float())
test_loss = mean_squared_error(y_test, y_pred.detach().numpy())
return test_loss
# 定义参数范围
param_ranges = [
(16, 256), # num_neurons
(0.1, 0.5), # dropout_rate
(16, 128), # batch_size
(0.001, 0.01), # learning_rate
]
# 定义优化器
num_particles = 20
num_dimensions = len(param_ranges)
max_iterations = 50
objective_func_partial = partial(objective_func, X_train=X_train, y_train=y_train)
cpso = CPSO(num_particles, num_dimensions, max_iterations, objective_func_partial)
# 进行优化
best_params = cpso.optimize()
# 解析最优参数
num_neurons, dropout_rate, batch_size, learning_rate = best_params
```
上面代码中,我们先加载训练集和测试集数据,然后定义目标函数`objective_func`,该函数接受一个参数`params`,表示模型的超参数,然后在训练集上训练模型,最后计算测试误差。我们还定义了一个`objective_func_partial`函数,该函数是`objective_func`的偏函数,用来传递训练集和测试集数据。
然后我们定义了参数范围`param_ranges`,用来指定每个超参数的取值范围。接着定义了优化器`cpso`,该优化器接受四个参数:`num_particles`表示粒子数,`num_dimensions`表示维度数,`max_iterations`表示最大迭代次数,`objective_func_partial`表示目标函数。在调用`cpso.optimize()`函数时,会返回最优的超参数。
最后,我们解析出最优的超参数,并将其传递给模型进行训练和测试。
在训练和测试模型后,我们可以使用如下代码绘制测试集的预测值和实际值,计算测试集的均方根误差(RMSE),并在预测集上进行预测:
```python
import matplotlib.pyplot as plt
# 计算测试误差
y_pred = model(torch.tensor(X_test.values).float())
test_loss = mean_squared_error(y_test, y_pred.detach().numpy())
test_rmse = np.sqrt(test_loss)
# 绘制测试集的预测值和实际值
plt.plot(y_test.values, label='True')
plt.plot(y_pred.detach().numpy(), label='Predicted')
plt.legend()
plt.show()
# 输出测试误差和RMSE
print('Test loss:', test_loss)
print('Test RMSE:', test_rmse)
# 在预测集上进行预测
X_pred = pd.read_csv('X_pred.csv')
y_pred = model(torch.tensor(X_pred.values).float())
# 计算警戒线
y_max = y_train.max().values[0]
warning_line = 0.85 * y_max
# 绘制预测集的实际值到达的时间和预测值到达的时间
y_pred_values = y_pred.detach().numpy().squeeze()
y_pred_times = np.argwhere(y_pred_values >= warning_line).squeeze()
plt.plot(y_pred_values, label='Predicted')
plt.axhline(y=warning_line, color='r', linestyle='--', label='Warning Line')
for i in y_pred_times:
plt.axvline(x=i, color='g', linestyle='--')
plt.legend()
plt.show()
```
上面代码中,我们先计算测试误差和RMSE,并绘制测试集的预测值和实际值。然后输出测试误差和RMSE。最后,我们加载预测集数据,使用模型进行预测,计算警戒线,绘制预测集的实际值到达的时间和预测值到达的时间。
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